Excavating machine



Feb 7, 1928.

A. T. HANSEN EXCAVATING MACHINE Filed March 13. 1926 2 Sheets-Sheet l Feb. 7, 1928.

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ALFRED '1. HANSEN, 0F GREEN BAY, WISCONSIN,

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Application filed March 13, 192a. serial No. same. i

This invention relates to excavating maces, particularly those of the type commonly known as power shovels, and has for its object the provision of means whereby a dipper may be given an outward thrust during upward movement without. detracting from the hoisting power.

It is well known that the ordinary type of power shovel includes a rotatable platform carrying a pivoted boom which, in turn, carries longitudinally movable members to which the dipper or digger is connected, drum and cable means being provided for raising the dipper, the dipper sticks of course swinging in a corresponding manner.

in devices of this class it has been customary to provide some means for moving the dipper sticks outwardly during the upward swin of the dipper in "order to take a deeper bite in a bank, or the like, being dug away. However, such expedients have heretofore possessed an objectionable feature inasmuch as the utilization of power for projecting the dipper sticks has involved a decrease in the hoisting power so that the action has not been as efiicient as desired.

it is with the above facts in view that I have designed the present invention which has for an important object the provision of a nov el drum structure mounted in the boom and having both the hoisting-and pull-back cables engaged therewith.

A more specific object is to provide an excavating machine in which the boom is equipped with a drum structure having portions of different diameters, the hoisting cable and pull-back cable being wrapped upon these respective portions, these cables being ada ted to travel back and forth in suitable gui e grooves, being of course controlled by actuation of the main drums which supply the hoisting and pull-back power. 7

Still another object is to provide. an excavating machine in which the peculiarly constructed drum is sunk within the boom, its shaft carrying gears or pinions meshing with rack teeth on the dipper sticks, the difierence in the sizeof the end portions of the drum providing an increase in leverage so that a more powerful outward thrust on the dipper may be had than is possible under ordinary circumstances where the usual type of uniform diameter drum is employed.

An additional object is to provide a drum dead-ended on this drum and being the operation of this .drum' structure and arrangement of this character which may bebuilt into any ordinary type of power shovel it being unnecessary to provlde a special construction throughout, the invention being simple and inexpensive to manufacture and easy to install in addition to possessing the ualities of efliciency and durability, and being an improvement in the art.

other objects and advantages, the invention consists in the combination and arrangement of parts and details of construction to be hereinafter more fully described and claimed, and illustrated in the accompanying drawings in which: 7

Figure 1 is a side elevation of a power shovel equipped with the invention, the lowered position of the dipper being shown by full lines and the elevated" and forwardly pushed position being indicated by dotted mes, Figure 2 is a top plan view, and

F gure 3 is a cross section through the boom taken on the line 3 3 of Figure 2, the specially constructed boom being shown in elevation. Referring more particularly to the drawings 1 have illustrated, in general, an ex- ,cavating machine or power shovel of a rather conventional type, certain details being, however, omitted as not essential to an understanding of the invention. It is well known that devices of this character embody a base 1 which is ordinarily mounted upon wheels or a caterpillar tread device aiid which carries a rotatable platform 2 on which are mounted a hoisting drum 3 and wpull-back drum 4:, the drums being geared together by the intermeshing gears 5 and 6, In devices of this type it is customar'y to provide each drum with a clutch and brake mechanism and these are indicated diagrammatically at 7' and 8.

Suitably pivoted at 9 upon the ,latform or other equivalent support is a boom 10 of trussed steel beam construction involving any preferred or necessary details so as to have the proper strength and rigidity though it will be noted that the central portion of this boom is open-for a reason to be explained. Any desired cables might be provided for raising and lowering the boom or, if preferred, any suitable anchor or guide means may be provided for bolding it rigid with respect to the face of the or To the atta nment of the foregoing and machine, these details being immaterial and not being illustrated. At the forward end of the boom is ashaft 11 carrying a palr of guide pulls s or sheaves 12 and 13 arranged for in ependent rotation. The numeral 14 designates a-pair of dipper sticks located at op osite sides of and in straddling relation to the boom, these sticks carrying the dipper or shovel device 15 which may be of any preferred construction and w ich carries a padlock sheave 16. v

In carr' ing out the invent on I rovide a skipper s aft-17 journaled in suita le bearings 18 on the opposite sides of the boom and carrying, at. its, ends, pinions 19 which mesh with racks 20 on the lower edges of the dipper sticks 14. The shaft 17 also carries a peculiarly constructed drum 21 which is sunk within the boom and which includes or is formed with two portions 22 and 23 of different diameters, the ratio of the former to the latter being preferably substantially 2:1. These respective portions are grooved as indicated at 24 and 25 so as to guide the cables, to be described, during their movement in the operation of the machine. At the ends of the drum are outstanding guard flanges 26 provided for the purpose preventing the cables from runmg ofi".

An im ortant feature in theconstruction of the s 'pper drum is the fact that the grooves 24 at the large end thereof constitute a continuation of or communicate with the grooves 25 at the smaller end so that both cables to be-dcscribed, may be capable of being wound upon the entire length of the drum at difi'erent times. In other words there must be a transitional groove between those on the large and small ends for guiding the cables from the small end onto thelarge end and vice versa. The reason for this unusual and novel construction will of course be explained. Y

Dead-ended to and wra ped about the hoisting drum 3 is a cab e. 27 which is trained over the guide pulley 12, under the padlock sheave 16, 'over the guide pulley 13 and then wrapped and dead-ended to the large rtion 22 of. the skipper drum 21. Seen to and wrapped about the drum 4 is a pull-back cable 28 which is also wrapped about'and dead-ended on the smaller portion 23 of the skipper drum.

In the o ration, when the machine has been place or spotted for the purpose of excavating, the hoisting lever, not shown, is thrpwn in, as is customary, and the dipper whlch is initially on the ground or near the place to be excavated starts to rise, the movement being in-the arc of a circle. Of course the dipper is so positioned that upon its upward movement it .will dig or bite into the ground. While the dipper is moving in this manner, the operator may desire to thrust it is prevented or 1s developed in hoisting... Th

mean? outwardly so as to increase the bite. This may be done'by releasing the brake rovided on the pull-back drum. As the hoist cable 27 is dead-ended. on the skipper drum 22, the tension of the hoist cable will cause the drum to revolve in an'anti-clockwise manner, (considering the machine as viewed from the left as in Figure 1) owing to the direction or pitch of'the grooves on the drum. The rotation of the drum of course causes corresponding movement of the pinions 19 and as these are in mesh with the racks 21 on the dipper sticks 14 the dipper sticks will, be thrust outwardly. If the operator sets the brake on the pull-back drum the crowding out or thrusting motion stopped and the dipper moves onl ap roximately in the arc of a circle of which t e skipper shaft is the center. The dipper and sticks can be moved inwardly or retracted by releasing the brake and throwing in the clutch on the pull-back drum. Thus the thrusting out and retraction can be accomplished while the dipper is being hoisted. It will be seen that the hoist cable 27 is'wound clockwise on the large end of the drum (considering the machine as viewed from the left as in Fig. 1?] and it will move onto the small end of t e drum when the dipper sticks are retracted. The pull-back upon the small end of the drum. When the cables are properly wrap ed and the drum properly grooved, while the skipper drum is revolving, one cable is always unwinding and. the other one is winding. When the dipper sticks are thrust outwardly the hoist ca le unwinds from the small end of the drum onto the large end, followed b the pull-back cable winding from the sma 1 end of the drum to the large end thereof.

From the foregoing it will be seen that when the dipper is thrust to a point about level with the free end of the boom, the hoist cable starts to unwrap from the large end of the skipper drum thereby giving the extra amount of thrusting out power necessary to project the dipper outward] of and above the pivot of the dipper stic namely the shaft 17. I have discovered that the extra power caused by unwrappipg from the large end of the drum gives a at twice the power for crowding out or thrusting as there e unwrapping above mentioned of course starts at the small end of the drum but the increase in power is not produced until the unwrappin reaches a point on the large end of the cfium. It is believed that the construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.

While I have shown and described a preferred embodiment of the invention, it should be understood that this is merely i1- cable 28 iswound anti-clockwise lustrative as it is conceivable that the skipper drum may be constructed in a somewhat different manner and that the relative proportions of the parts may be varied it found advisable for any reason. I reserve the right to make any such modifications and in fact all changes or variations which will not constitute any departure from the spirit of the invention or the scope ot the subjoined claims.

Having thus described the invention, I claim:

1. lin an excavating machine, coasting hoisting and pullback drums, a boom carrying guide sheaves, a shaft journaled at the intermediate portion of the boom and carrying gears, dipper sticks slidably mounted with respect to the boom and carrying a dipper, the dipper sticks including racks meshing with said gears, a skipper drum said shaft, a cable dead-ended and wrapped upon the hoisting drum, trained over the guide sheaves, connected with the dipper and dead-ended and wrapped upon one end of said skipper drum, and a cable deadended and wrapped upon the pull-- back drum and dead-ended and wrapped upon the other end of the skipper drum, said skipper drum having portions of different diameters and being termed throughout its length with a continuous cable guiding groove.

2. in an excavating machine, coacting hoisting and pullback drums, a boom carrying guide sheaves, a shaft journaled at the intermediate portion of the boom and carrying gears, dipper sticks slidably mounted with respect to the boom and carrying a dipper, the dipper sticks including racks meshing with said gears, a skipper drum on said shaft, a cable dead-ended and wrapped upon the hoisting drum, trained over the guide sheaves, connected with the dipper and deadended and wrapped upon one end of said skipper drum, and a. cable deadended and wrapped upon the pull-back drum and dead-ended and wrapped upon the other end of the skipper drum, the skipper drum having one end of considerably greater diameter than the other, and being grooved throughout its length, said cables being initially wound upon the respective end portions and being capable of traversing the length of the drum.

3. In an excavating machine, coacting hoisting and pull-back drums, a boom carrying guide sheaves, a shaft journaled at the intermediate portion of the boom and carryin gears, dipper sticks slidably mounte with respect to the boom and carrying a dipper, the dipper sticks including racks meshing with said gears, a skipper drum. on said shaft, a cable dead-ended and wrapped upon the hoisting drum, trained over the guide sheaves, connected with the dipper and dead-ended and wrapped upon one end of said skipper drum, and a cable dead-ended and wrapped upon the pullback drum and dead-ended and wrapped upon the other end of the skipper drum, the drum having its opposite ends of widely ditterent diameters and being formed with a continuous guide groove, the cables being initially wound upon the respective end portions and one being wound in the opposite direction to the other, both cables being capable of traversing the entire length of the drum and acting to control the thrust or retraction of the dipper sticks.

i. in an excavating machine including a boom, dipper sticks, a dipper, a hoisting drum and a pull-back drum, a skipper drum sunk within the boom and opcratively connected with the dipper sticks for moving the same longitudinally, a hoisting cable moved by the hoisting drum, connected with the dipper and secured to and wrapped about the skipper drum in one direction, and a pullback cable connected with the pullback drum and secured to and wrapped about the skipper drum in the opposite direction to the winding of the hoisting cable, and means on the drum permitting both cables to traverse substantially the full length thereof and to increase the outward thrust of the dipper sticks at certain times.

5. In an excavating machine, the combination of a boom carrying guide sheaves, a shaft journaled at the intermediate portion of the boom, dipper sticks slidably mounted along the boom and operatively driven by said shaft, a hoisting drum, a pull-back drum, and a skipper drum on said shaft, the skipper drum having its opposite end portions of widely different diameter and being formed throughout its length with a continuous groove extending about both end portions, a dipper, a cable dead-ended and wrapped upon the hoisting drum, trained over the guide sheaves, connected with the dipper and dead-ended and wrapped upon the smaller end of the skipper drum, and a cable dead-endedand wrapped-upon the pull-back drum and deadended and wrapped upon the larger end of the skipper drum, both cables being capable of traversing the entire length of the skip per drum and each being adapted to pass from the larger to the smaller end thereof, and vice versa, whereby to increase the crowding-out power.

In testimony whereof I affixmy signature.

ALFRED T. HAN SEN.

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